import * as types from './mutation-types'
import {playMode} from '../common/js/config'
import {shuffle} from '../common/js/util'
import {saveSearch, deleteSearch, clearSearch, savePlay,saveFavorite, deleteFavorite} from '../common/js/cache'

function findIndex(list, song) {
    return list.findIndex((item) => {
        return item.id === song.id
    })
}

export const selectPlay = function ({commit, state},{list,index}) {
    commit(types.SET_SEQUENCE_LIST, list)
    if(state.mode ===playMode.random) {
        let randomList = shuffle(list)
        commit(types.SET_PLAYLIST, randomList)
        index = findIndex(randomList, list[index])
    } else {
        commit(types.SET_PLAYLIST, list)
        
    }
    commit(types.SET_CURRENT_INDEX, index)
    commit(types.SET_FULL_SCREEN, true)
    commit(types.SET_PLAYING_STATE, true)
}

export const randomPlay = function({commit},{list}) {
    commit(types.SET_PLAY_MODE, playMode.random)
    commit(types.SET_SEQUENCE_LIST, list)
    let randomList = shuffle(list)
    commit(types.SET_PLAYLIST, randomList)
    commit(types.SET_CURRENT_INDEX, 0)
    commit(types.SET_FULL_SCREEN, true)
    commit(types.SET_PLAYING_STATE, true)
}

export const insertSong = function ({commit, state}, song) {
    let playlist = state.playlist.slice()//slice()创建副本
    let sequenceList = state.sequenceList.slice()
    let currentIndex = state.currentIndex
    //记录当前歌曲
    let currentSong = playlist[currentIndex]
    //查找当前列表中是否有待插入的歌曲并返回其索引
    let fpIndex = findIndex(playlist, song)
    //因为是插入歌曲，所以索引+1
    currentIndex++
    //插入这首歌到当前索引位置
    playlist.splice(currentIndex, 0, song)
    //如果已经包含这首歌
    if(fpIndex > -1) {
        //如果当前插入的序号大于列表中的序号
        if(currentIndex > fpIndex) {
            playlist.splice(fpIndex, 1)
            currentIndex--
        } else {
            playlist.splice(fpIndex + 1, 1)
        }
    }

    let currentSIndex = findIndex(sequenceList, currentSong) + 1

    let fsIndex = findIndex(sequenceList, song)

    sequenceList.splice(currentSIndex, 0, song)

    if(fsIndex > -1) {
        if(currentSIndex > fsIndex) {
            sequenceList.splice(fsIndex, 1)
        } else {
            sequenceList.splice(fsIndex + 1, 1)
        }
    }

    commit(types.SET_SEQUENCE_LIST, sequenceList)
    commit(types.SET_PLAYLIST, playlist)
    commit(types.SET_CURRENT_INDEX, currentIndex)
    commit(types.SET_FULL_SCREEN, true)
    commit(types.SET_PLAYING_STATE, true)
}

export const saveSearchHistory = function ({commit}, query) {
    commit(types.SET_SEARCH_HISTORY, saveSearch(query))
}

export const deleteSearchHistory = function ({commit}, query) {
    commit(types.SET_SEARCH_HISTORY, deleteSearch(query))
}

export const clearSearchHistory = function ({commit}) {
    commit(types.SET_SEARCH_HISTORY, clearSearch())
}

export const deleteSong = function ({commit, state}, song) {
    let playlist = state.playlist.slice()//slice()创建副本
    let sequenceList = state.sequenceList.slice()
    let currentIndex = state.currentIndex
    let pIndex = findIndex(playlist, song)
    playlist.splice(pIndex, 1)
    let sIndex = findIndex(sequenceList, song)
    sequenceList.splice(sIndex, 1)

    if(currentIndex > pIndex || currentIndex === playlist.length) {
        currentIndex--
    }

    commit(types.SET_PLAYLIST, playlist)
    commit(types.SET_SEQUENCE_LIST, sequenceList)
    commit(types.SET_CURRENT_INDEX, currentIndex)

    const playingState = playlist.leng > 0
    commit(types.SET_PLAYING_STATE, playingState)
}

export const deleteSongList = function ({commit}) {
    commit(types.SET_PLAYLIST, [])
    commit(types.SET_SEQUENCE_LIST, [])
    commit(types.SET_CURRENT_INDEX, -1)
    commit(types.SET_PLAYING_STATE, false)
}

export const savePlayHistory = function ({commit}, song) {
    commit(types.SET_PLAY_HISTORY, savePlay(song))
}

export const saveFavoriteList = function ({commit}, song) {
    commit(types.SET_FAVORITE_LIST, saveFavorite(song))
}

export const deleteFavoriteList = function ({commit},song) {
    commit(types.SET_FAVORITE_LIST, deleteFavorite(song))
}